Objective In response to the increasing rates of suicide in military personnel throughout the world, there is an increasing focus on the development and implement of interventions aimed at preventing suicide among this group. Therefore, the goal of the present systematic review was to examine the effectiveness of interventions focused on preventing suicidal ideation and behavior in military personnel. Method Search for articles was conducted in PsycINFO, PubMed, Web of Science, EMBASE, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), IranMedex, Scientific Information Database (SID), and MagIran. International databases were searched from June 2008 to May 2019, and Iranian databases were searched from their inception to May 2019. RCT and non-RCT studies focused on the effectiveness of preventive interventions for suicide in military personnel were included in the analysis. Narrative synthesis of results was the main strategy for data analysis. Results According to the inclusion and exclusion criteria, 18 articles were selected. Interventions were divided into four categories according to their nature: interventions based on psychotherapy, interventions based on crisis management, interventions based on pharmacotherapy, and community-based interventions. In addition, most studies had moderate methodological quality. Conclusion Most of the preventive interventions were effective in reducing suicidal ideation and behavior in military personnel; however, in some cases, there were serious challenges in terms of effectiveness. Interventions based on cognitive-behavioral approaches constitute a significant portion of the interventions. Overall, RCTs and non-RCTs, especially community-based studies, need to use more rigorous examinations in order to gain research and clinical support.